A thrombus, or blood clot, is the final product of the blood coagulation step in hemostasis. Thrombi can form in various parts of the human vasculature, such as in blood veins and arteries. For example, if a thrombus forms in a small artery, it may completely block the flow of blood through the artery, leading to necrosis of the tissue supplied by the blood vessel. If the thrombi become dislodged, forming emboli, they can cause serious conditions such as an ischemic stroke. Therefore, many techniques have been developed for the removal of thrombi. This procedure is commonly referred to as a thrombectomy.
A thrombectomy is typically performed using a catheter. In some instances, the catheter is outfit with an inflatable balloon attached to its tip. This is commonly referred to a Fogarty catheter. The catheter tip is passed beyond the clot, the balloon is inflated, and the thrombus is removed by withdrawing the catheter. The inflatable balloon may also be used to administer pharmacologic treatment wherein thrombolytic agents (e.g., streptokinase, urokinase, tissue plasminogen activator (TPA)) and/or anticoagulant drugs (e.g., heparin, warfarin) are administered in an effort to dissolve and prevent further growth of the clot. Possible complications of balloon thrombectomy include endothelial denudation, vessel wall injury, and intimal lesions, which can lead to another thrombosis. The vessel may also be affected by a dissection or rupture or causing cholesterol embolism from atherosclerotic plaques.
Catheter thrombectomy may also be performed using aspiration, wherein the thrombus is removed by suction, or by surgical thrombectomy, wherein the thrombus is detached by surgical removal following incision into the blood vessel by open surgery. Open surgical thrombus-removing procedures can, in many cases, be used to rapidly remove clots from the lumens of blood vessels, but such open surgical procedures are notoriously invasive, often require general anesthesia, and the use of such open surgical procedures is generally limited to blood vessels which are located in surgically accessible areas of the body. For example, many patients suffer strokes due to the lodging of blood clots in small arteries located in surgically inaccessible areas of their brains and, thus, are not candidates for open surgical treatment.
Thus, there exists a need for the development of new surgical thrombectomy catheter that is advanceable and exchangeable over pre-inserted small diameter guidewires and that is capable of safely removing thrombi or other matter from blood vessels.